The present invention relates to a spectral image sensor device for acquiring a spectral image in a predetermined wavelength range.
A hyper-spectral camera is known as one of spectral image sensor devices for acquiring a spectral image. The hyper-spectral camera is an image pickup device for separating a light from an object to be measured to a plurality of wavelength ranges as defined by hyper-spectra and for acquiring an image for each of the wavelength ranges. The hyper-spectral camera is primarily mounted on board of an artificial satellite or on an aircraft and is applied in agricultural and environmental or other purposes. In future, it is expected to be used in the fields of medical services, food industry, etc.
The hyper-spectral camera separates a light passing through a slit, which fulfills the function as a diaphragm of field of view, to spectral components through a diffraction grating, and acquires a spectral image for field of view of the slit. By moving the slit, the hyper-spectral camera acquires a spectral image of field of view of the camera.
However, the conventional type hyper-spectral camera can obtain only a one-dimensional spectral image at one time because the conventional type hyper-spectral camera takes images by separating the light in a limited range to spectral components through a diaphragm of field of view by the diffraction grating. Further, higher cost is required because the diffraction grating is very expensive.
The Japanese Patent Publication JP-A-2011-89895 discloses a hyper-spectral image pickup device and a hyper-spectral image pickup method, which makes the light from an object to be photographed pass through a slit, separates the light passing through the slit is to a plurality of wavelength ranges via the diffraction grating, makes an image sensor receive the light for each of the wavelength ranges separated and produces a two-dimensional image based on the light received by the image sensor.